Effect of trace mineral source on lactation performance, claw integrity, and fertility of dairy cattle

Two hundred fifty multiparous and primiparous cows were assigned to a study at approximately 70 d prepartum to determine the effect of trace mineral source on lactation performance, claw integrity, and fertility. Cows received treatments from 3 wk prepartum through wk 35 postpartum. Treatments consisted of 1) all supplemental Zn, Mn, Cu, and Co provided in sulfate form (Sulfate) and 2) 360 mg of Zn, 200 mg of Mn, 125 mg of Cu, and 12 mg of Co supplied daily by Sulfate minerals replaced with similar amounts of minerals supplied by Availa-4 (CTM). Individuals involved with daily animal care or data recording, or both, were blinded to treatment assignments. Cows from all treatments were housed in common pens, and treatments were dispensed to cows via a computerized feeder. All claws of cows were examined before treatment administration and at 16 and 36 wk postpartum by personnel trained in identifying claw lesions. Cows fed the CTM diet tended to produce more milk and energy-corrected milk than cows fed the Sulfate diet. Cows fed the CTM diet also produced more milk protein and solids (fat + protein) than cows fed the Sulfate diet. Replacing Sulfate minerals with those supplied by CTM decreased incidence of sole ulcers at wk 36 postpartum and tended to decrease incidence of interdigital dermatitis at wk 16 and 36 postpartum. Severity of heel erosion tended to be less for cows fed CTM than cows receiving the Sulfate diet. Despite first service conception rates tending to be greater for cows fed the Sulfate diet, there was no effect of treatment on rate of conception. A greater percentage of cows fed the Sulfate diet tended to be culled from the herd before wk 36 postpartum than cows fed the CTM diet. Replacing Sulfate minerals with CTM resulted in improved lactation performance and claw integrity.     

Short communication: Effects of supplementing diets of Holsteins with copper,zinc, and manganese on blood neutrophil function

The effects of supplementing diets with sulfate or glycinate Cu, Zn, and Mn on blood neutrophil function were examined in 27 late-lactation Holstein cows having a mean (± standard deviation) days in milk at time of neutrophil assays of 216 ± 31 d. Cows were assigned to 9 blocks of 3 and were grouped by parity, milk production, and days in milk. Cows within each block were randomly assigned to 1 of 3 treatments: (1) control diet devoid of supplemental Cu, Zn, and Mn; (2) diet supplemented with Cu, Zn, and Mn via sulfates; and (3) diet supplemented with Cu, Zn, and Mn via glycinate form. All cows were initially fed a control total mixed ration with basal mineral concentrations of 8 mg/kg of Cu, 35 mg/kg of Zn, and 35 mg/kg of Mn for 30 d. During the treatment period, cows fed diets with mineral supplementation via sulfates or glycinate forms had target total dry matter dietary concentrations of 18 mg/kg of Cu, 60 mg/kg of Zn, and 60 mg/kg of Mn for 30 d. Control cows were fed the control diet devoid of supplemental minerals for an additional 30 d. In vitro neutrophil functions were measured after 30 d on experimental or control diets. Percentage of neutrophils phagocytizing, intracellular kill, and phagocytic index did not differ among treatments. Serum concentrations of Cu, Zn, and Mn were also not affected by dietary treatment after 30 d. Results from this study demonstrated that dietary Cu, Zn, and Mn supplemented either as sulfates or glycinate form for 30 d had no effect on either in vitro blood neutrophil function or serum concentrations of Cu, Zn, and Mn in late-lactation Holstein cows.     

Effect of trace mineral supplementation on selected minerals,energy metabolites,oxidative stress,and immune parameters and its association with uterine diseases in dairy cattle

The objective of this study was to evaluate the relationship between selected minerals’ serum levels, energy metabolites, oxidative stress indicators, IL-8 and haptoglobin levels, and the potential for uterine diseases. Additionally, we investigated the effect of injectable trace mineral supplementation (ITMS) on metabolism, immune function, and animal health under field conditions involving a dairy herd with high milk production. The study was conducted in 1 dairy farm located near Ithaca, New York, with 270 multiparous cows were enrolled from October 3, 2012 until January 10, 2013. Cows were randomly allocated into 1 of 2 treatments groups: ITMS or control. Cows randomly assigned to the ITMS group received 2 injections of trace minerals at 230 and 260 d of gestation; each injection contained 300 mg of Zn, 50 mg of Mn, 25 mg of Se, and 75 mg of Cu. Retained placenta (RP) and metritis were diagnosed and treated by trained farm personnel. Clinical endometritis evaluation was performed by the investigators. Blood mineral levels, plasma nonesterified fatty acids and serum β-hydroxybutyrate concentrations, plasma IL-8 concentrations, serum haptoglobin concentration, and serum superoxidase dismutase and plasma glutathione peroxidase activities were measured at various time points before and after calving. Four groups of mixed general linear models were fitted to the data using MIXED procedure of SAS. Injectable trace mineral-supplemented cows had increased serum concentration of Cu, Se, and Zn. Conversely, ITMS did not affect energy metabolites or immune and oxidative stress parameters. Serum concentration of Ca, Cu, K, Mg, Mo, Ps, Pt, Se, and Zn varied according to days relative to parturition. Cows with RP had reduced serum concentrations of Ca, Mg, Mo, and Zn when compared with cows without RP. Cows affected with metritis had significantly lower serum concentrations of Ca, Mo, soluble P, total P, Se, and Zn than nonaffected cows. Serum concentration of Ca, Cu, Mo, and Zn were reduced in cows diagnosed with endometritis in comparison to nonaffected ones.     

Macromineral and trace element concentrations in milk from Finnish Ayrshire cows fed microalgae (Spirulina platensis) and rapeseed (Brassica napus)

Given the lack of research regarding the effect of microalgal supplementation in dairy cows on milk mineral concentrations, this study investigated the effect of feeding different protein supplements in dairy cow diets on milk, feces, and blood plasma mineral concentrations, associated milk and blood plasma transfer efficiencies, and apparent digestibility. Lactating Finnish Ayrshire cows (n = 8) were allocated at the start of the trial to 4 diets used in a replicated 4 × 4 Latin square design experiment: (1) control diet (CON), (2) a pelleted rapeseed supplement (RSS; 2,550 g/d), (3) a mixture of rapeseed and Spirulina platensis (RSAL; 1,280 g of RSS + 570 g of S. platensis per day), and (4) S. platensis (ALG; 1,130 g of S. platensis per day). In each of the 4 experimental periods, a 2-wk adaptation to the experimental diets was followed by a 7-d sampling and measurement period. Feed samples were composited per measurement period, milk, and feed samples (4 consecutive days; d 17–20), and blood plasma samples (d 21) were composited for each cow period (n = 32). Data were statistically analyzed using a linear mixed effects model with diet, period within square, square and their interaction as fixed factors, and cow within square as a random factor. Cows fed ALG were not significantly different in their milk or blood plasma mineral concentrations compared with CON, although feeding ALG increased fecal concentrations of macrominerals (Ca and Mg) and trace elements (Co, Cu, Fe, I, Mn, and Zn), and reduced their apparent digestibility, compared with CON. When compared with CON and ALG, milk from cows fed RSAL and RSS had lower milk I concentrations (?69.6 and ?102.7 μg/kg of milk, respectively), but total plasma I concentrations were not affected significantly. Feeding S. platensis to dairy cows did not affect mineral concentrations in cows' blood or milk, but care should be taken when rapeseed is fed to avoid reducing milk I concentrations which may in turn reduce consumers' I intake from milk and dairy products.     

Effect of selenium source on selenium status, neutrophil function, and response to intramammary endotoxin challenge of dairy cows

The effects of feeding dry and early lactation dairy cows diets with selenate or selenized yeast (Se-yeast) on concentrations of Se in serum, milk, and newborn calves, neutrophil function, and inflammatory response were determined. At 60 d before anticipated calving until approximately 30 d in milk (DIM), cows were fed diets that contained 0.3 mg of supplemental Se/kg of DM from sodium selenate or Se-yeast. Diets also contained 0.2% supplemental S (as sulfate) because it has been shown to reduce absorption of Se by dairy cows. The concentration of Se in serum at calving and 28 DIM was about 1.4 times greater for cows fed Se-yeast than for those fed selenate. Serum concentrations decreased 45 and 23% from dry-off to calving for cows fed selenate or Se-yeast, respectively. Selenium concentrations in serum from newborn calves were also about 1.4 times greater when the dams were fed Se-yeast. Concentrations of Se in colostrum and milk were about 1.8 times greater when cows were fed Se-yeast. Blood neutrophils were isolated from cows at 28 DIM and were used in an in vitro kill assay. Selenium treatment did not affect bacterial kill or the percentage of neutrophils that phagocytized bacteria. At approximately 28 DIM, one quarter from each cow was infused with a solution containing endotoxin. Peak body temperature (40.7°C) occurred 6 h postinfusion, and peak somatic cell count (6.5 log₁₀/mL) occurred at 12 h postinfusion. Neither measure was influenced by Se treatment.     

Effects of replacing inorganic salts of trace minerals with organic trace minerals in pre- and postpartum diets on feeding behavior,rumen fermentation,and performance of dairy cows

Our objectives were to evaluate the effects of complete replacement of supplementary inorganic salts of trace minerals (STM) by organic trace minerals (OTM) in both pre- and postpartum diets on feeding behavior, ruminal fermentation, rumination activity, energy metabolism, and lactation performance in dairy cows. Pregnant cows and heifers (n = 273) were blocked by parity and body condition score and randomly assigned to either STM or OTM diets at 45 ± 3 d before their expected calving date. Both groups received the same diet, except for the source of trace minerals (TM). The STM group was supplemented with Co, Cu, Mn, and Zn sulfates and Na selenite, whereas the OTM group was supplemented with Co, Cu, Mn, and Zn proteinates and selenized yeast. Treatments continued until 156 days in milk and pre- and postpartum diets were formulated to meet 100% of recommended levels of each TM in both treatments, taking into consideration both basal and supplemental levels. Automatic feed bins were used to assign treatments to individual cows and to measure feed intake and feeding behavior. Rumination activity was monitored by sensors attached to a collar from wk ?3 to 3 relative to calving. Blood metabolites were evaluated on d ?21, ?10, ?3, 0, 3, 7, 10, 14, 23, and 65 relative to calving. Ruminal fluid samples were collected using an ororuminal sampling device on d ?21, 23, and 65 relative to calving, for measurement of ruminal pH and concentration of volatile fatty acids. Cows were milked twice a day and milk components were measured monthly. Cows supplemented with OTM tended to have longer daily feeding time (188 vs. 197 min/d), and greater dry matter intake (DMI; 12.9 vs. 13.3 kg), and had a more positive energy balance (3.6 vs. 4.2 Mcal/d) and shorter rumination time per kg of dry matter (DM; 40.1 vs. 37.5 min/kg of DM) than cows supplemented with STM during the prepartum period. In the postpartum period, OTM increased DMI in multiparous cows (24.1 vs. 24.7 kg/d) but not in primiparous cows (19.1 vs. 18.7 kg/d). The difference in DMI of multiparous cows was more evident in the first 5 wk of lactation, when it averaged 1 kg/d. Milk yield was not affected by treatment in multiparous cows (44.1 vs. 44.2 kg/d); however, primiparous cows supplemented with OTM had lesser yields than primiparous cows supplemented with STM (31.9 vs. 29.8 kg/d). Cows supplemented with OTM had a greater percentage of protein in milk (3.11 vs. 3.17%), reduced concentration of nonesterified fatty acids in serum (0.45 vs. 0.40 mmol/L), and rumination activity (30.1 vs. 27.8 min/kg of DM) than cows supplemented with STM. At the end of the transition period, cows supplemented with OTM had reduced molar proportion of acetate, reduced pH, and tended to have a greater concentration of total volatile fatty acids in ruminal fluid. In conclusion, complete replacement of STM by OTM caused modest changes in rumen fermentation, feeding behavior, energy metabolism, and performance of dairy cows, improving postpartum DMI in multiparous cows and reducing circulating levels of nonesterified fatty acids. The pre-absorptive effects of TM source and the parity specific responses on performance warrant further research.     

Effect of replacing a portion of inorganic chloride trace minerals with trace mineral amino acid complexes

The objective was to determine whether replacing a portion of inorganic chloride trace minerals and cobalt carbonate in the diet with AA complexes of trace minerals and cobalt glucoheptonate will improve lactating cow performance, feed efficiency, and calf performance. In a clinical trial, 69 Holstein cows entering second lactation and greater were randomly assigned to 1 of 2 treatments, with the total dietary trace mineral concentration the same between treatments, starting 1 wk after dry off (50 to 57 d before expected parturition) until 154 d in milk (DIM): (1) an inorganic chloride trace mineral (ITM) blend consisting of Zn (75 mg/kg), Mn (65 mg/kg), and Cu (10 mg/kg) as hydroxychlorides and Co (1 mg/kg) as carbonate (n = 37) or (2) partial replacement of ITM with AA complexes of Zn (40 mg/kg), Mn (20 mg/kg), and Cu (3.5 mg/kg) and Co glucoheptonate (1 mg/kg; AATM; Availa-Dairy, Zinpro Corp.; n = 32). Dry matter intake (DMI) was recorded daily from enrollment through wk 8, and milk yields were recorded daily from calving through wk 22. Milk composition and body weights (BW) were collected weekly. Serum samples were analyzed for albumin (Alb), cholesterol (Chol), total bilirubin (Bili), aspartate aminotransferase (AST), haptoglobin, β-hydroxybutyrate (BHB), and Ca. A liver health index (LHI) was calculated based on Bili, Chol, and Alb concentrations. A liver functionality index (LFI) was calculated to standardize changes in Alb, Chol, and Bili from 4 to 29 DIM. Greater LHI and LFI indicate better health status. Colostrum was analyzed for IgG and Brix, and calf serum was analyzed for IgG. Calf growth was monitored through 9 wk of age (AATM: n = 12, ITM: n = 10). Data were analyzed using SAS software with mixed effects models and repeated-measures analysis, when applicable. Survival analysis for pregnancy by 154 DIM was analyzed by Cox proportional and Kaplan-Meier hazards models. Disorder incidence was tested with Fisher's exact test. Prepartum DMI as a percent of BW was lower in cows fed AATM and not significant postpartum. Cows fed AATM produced more milk from wk 1 to 8 and from wk 1 to 22. Energy-corrected milk yield and colostrum measures did not significantly differ between treatments. A treatment by time interaction was seen for AST and BHB; cows fed AATM tended to have lower AST concentrations at 28 DIM and lower concentrations in BHB through 29 DIM, though not statistically significant. Cows fed AATM had greater LHI at 4 DIM. Haptoglobin, Ca, LFI, hazard of pregnancy, risk to first service, survival curves, or services per pregnancy did not significantly differ. Calf serum IgG and birth weight did not significantly differ between treatments. Calves from dams fed AATM had greater average daily gain than calves from dams fed ITM. Overall, cows fed AATM during the dry period and early lactation had improved postpartum performance and potential health improvements.     

Effect of source of trace minerals in either forage- or by-product–based diets fed to dairy cows: 1. Production and macronutrient digestibility

Excess rumen-soluble Cu and Zn can alter rumen microbial populations and reduce fiber digestibility. Because of differences in particle size and chemical composition, ruminal and total-tract digestibility of fiber from forage- and by-product–based diets can differ. We hypothesized that, because of differences in mineral solubility, diets with hydroxy rather than sulfate trace minerals would have greater fiber digestibility, but the effect may depend on source of fiber. Eighteen multiparous cows were used in a split-plot replicated Latin square with two 28-d periods to evaluate the effects of Cu, Zn, and Mn source (sulfates or hydroxy; Micronutrients USA LLC, Indianapolis, IN) and neutral detergent fiber (NDF) source (forage diet = 26% NDF vs. by-product = 36%) on total-tract nutrient digestibility. During the entire experiment (56 d) cows remained on the same fiber treatment, but source of supplemental trace mineral was different for each 28-d period so that all cows were exposed to both mineral treatments. During each of the two 28-d periods, cows were fed no supplemental Cu, Zn, or Mn for 16 d followed by 12 d of feeding supplemental Cu, Zn, and Mn from either sulfates or hydroxy sources. Supplemental minerals for each of the mineral sources fed provided approximately 10, 35, and 32 mg/kg of supplemental Cu, Zn, and Mn, respectively, for both fiber treatments. Total dietary concentrations of Cu, Zn, and Mn were approximately 19, 65, and 70 mg/kg for the forage diets and 21, 85, and 79 mg/kg for the by-product diets, respectively. Treatment had no effect on dry matter intake (24.2 kg/d) or milk production (34.9 kg/d). Milk fatty acid profiles were altered by fiber source, mineral source, and their interaction. Cows fed the by-product diets had lower dry matter (65.9 vs. 70.2%), organic matter (67.4 vs. 71.7%), and crude protein digestibility (58.8 vs. 62.1%) but greater starch (97.5 vs. 96.3%) and NDF digestibility (50.5 vs. 44.4%) compared with cows fed the forage treatment. Feeding increased concentrations of by-products decreased total digestible nutrients regardless of mineral source. Feeding hydroxy Cu, Zn, and Mn increased NDF digestibility (48.5 vs. 46.4%) but had no effect on total digestible nutrients.     

Effects of replacing inorganic salts of trace minerals with organic trace minerals in the diet of prepartum cows on quality of colostrum and immunity of newborn calves

Our objectives were to evaluate the impact of supplementary trace mineral (TM) form—inorganic salts (STM; Co, Cu, Mn, Zn sulfates, and Na selenite) or organic (OTM; Co, Cu, Mn, Zn proteinates, and selenized yeast)—in the prepartum diet on quantity and quality of colostrum, passive immunity, antioxidant biomarkers, cytokine responses to lipopolysaccharide (LPS), health, and growth of newborn calves. Pregnant heifers (n = 100) and cows (n = 173) were enrolled at 45 d before calving, blocked by parity and body condition score, and allocated randomly to STM (50 heifers; 86 cows) or OTM (50 heifers; 87 cows) supplementation. Cows in both treatments were fed the same diet, except for the source of supplementary TM. Within 2 h of calving, dams and calves were separated, colostrum was harvested, the yield was measured, and a sample was saved for posterior analyses of colostrum quality. A subgroup of calves (n = 68) had a blood sample collected before colostrum feeding. After colostrum feeding, all samples and data collection were limited to 163 calves (STM = 82; OTM = 81) fed 3 L of good quality (Brix% >22) maternal colostrum via nipple bottle minutes after harvesting. Concentration of IgG in colostrum and serum was determined 24 h after colostrum feeding using radial immunodiffusion. Concentration of TM in colostrum and serum were performed by inductively coupled plasma mass spectrometry. Activity of glutathione peroxidase, ferric reducing ability of plasma, and concentration of superoxide dismutase were evaluated in plasma by colorimetric assays. Ex vivo whole blood stimulation with LPS was performed on d 7 of life to evaluate cytokine responses in a subgroup of 66 calves. Health events were recorded from birth to weaning, and body weight was recorded at birth (all calves) and on d 30 and 60 (heifers only). Continuous variables were analyzed by ANOVA and binary responses were analyzed by logistic regression. Complete replacement of STM by OTM in prepartum diet resulted in greater concentration of Se (461 vs. 543 ± 7 μg/g; ± SEM) but did not alter the concentration or total mass of other TM and IgG in colostrum. Female calves of the OTM group had greater concentration of Se in serum at birth (0.23 vs. 0.37 ± 0.05 μg/mL), were lighter in weight at birth (40.9 vs. 38.8 ± 0.6 kg) and weaning (93.2 vs. 89.7 ± 1.6 kg) than those of the STM group. Maternal treatments did not affect passive immunity or antioxidant biomarkers. On d 7, basal concentrations (log₁₀ of concentration in pg/mL) of IFNγ (0.70 vs. 0.95 ± 0.083) and LPS-stimulated concentrations of CC chemokine ligand 2 (CCL2; 2.45 vs. 2.54 ± 0.026), CC chemokine ligand 3 (CCL3; 2.63 vs. 2.76 ± 0.038), IL-1α (2.32 vs. 2.49 ± 0.054), and IL-1β (3.62 vs. 3.86 ± 0.067) were greater in OTM than in STM. Supplementation with OTM in pregnant heifers, but not in pregnant cows, reduced the incidence of preweaning health problems in their calves (36.4 vs. 11.5%). Complete replacement of STM by OTM in the prepartum diet did not cause major changes in colostrum quality, passive immunity, and antioxidant capacity, but increased cytokine and chemokine responses to LPS on d 7 of life and benefited preweaning health of calves born to primiparous cows.     

Mineral content of milk, colostrum, and serum as affected by physiological state and mineral supplementation

A 22-mo experiment was conducted to determine effects of mineral supplementation of cows on mineral elements in milk, colostrum, and blood serum. Purebred Brahman beef cows grazing pastures grown on sandy and well-drained soils were allotted to three treatments of 12 cows each as follows: control, a complete commercial mineral mixture, control plus dietary and injected Se, and control plus fortified mineral mixture. Milk and serum were analyzed for minerals 2 consecutive yr at parturition and 3 mo postpartum. Mean cow serum, Ca, Mg, P, and packed cell volume values were higher at parturition than 3 mo later, whereas serum Cu was highest at 3 mo. Mean serum concentrations were affected by year with higher Ca and hemoglobin and lower Cu concentrations in 1982 than in 1981. Increasing dietary Se resulted in higher serum Se. Colostrum was higher in Mg, P, Cu, Fe, Se, and Zn than milk, whereas milk was higher than colostrum in Mn. Means for treatment X time showed cows fed dietary and dietary plus injected Se and vitamin E had more Se in milk than milk from cows fed no supplemental Se.     

An evaluation of an immunomodulatory feed ingredient in heat-stressed lactating Holstein cows: Effects on hormonal,physiological, and production responses

Holstein cows (n = 30) were balanced by days in milk, milk production, and parity (91 ± 5.9 d in milk, 36.2 ± 2.5 kg/d, and 3.1 ± 1.4, respectively) and fed OmniGen-AF (OG; Phibro Animal Health, Teaneck, NJ), an immune stimulant, at 0 g/cow per d for control (CON) or 56 g/cow per d for OG for 52 d on a commercial dairy. At 52 d of the study cows were randomly selected (n = 12) from both groups (6 OG and 6 CON) and housed in environmentally controlled rooms at the Agricultural Research Complex for 21 d at the University of Arizona. Cows were subjected to 7 d of thermoneutral (TN) conditions, 10 d of heat stress (HS), and 4 d of recovery (REC) under TN conditions. Feed intake, milk production, and milk composition were measured daily. Rectal temperatures (RT) and respiration rates (RR) were recorded 3 times per day (600, 1400, and 1800 h). Blood samples were taken on d 7 (TN), 8 (HS), 10 (HS), 17 (HS), and 18 (TN) during the Agricultural Research Complex segment. Cows in HS had higher RR and RT and water intake and lower dry matter intake and milk yield than these measures in TN. There was a treatment × environment interaction with cows fed OG having lower RR and RT and higher dry matter intake during peak thermal loads than CON. However, milk yield did not differ between groups. Cows fed OG had lower milk fat percent than CON (3.7 vs 4.3%) during HS. The SCC content of milk did not differ between treatment groups but rose in both groups during the REC phase following HS. Plasma insulin and plasma glucose levels were not different between groups. However, plasma insulin in both groups was lower during acute HS, then rose across the HS period, and was highest during the REC phase. Plasma cortisol levels were highest in all cows on the first day of HS (d 8) but were lower in cows fed OG compared with CON. However, plasma ACTH concentrations were elevated in OG-fed animals at all times samples were collected. Plasma ACTH was also elevated in cows fed both OG and CON during HS. Feeding OG reduced plasma cortisol during acute but not chronic HS and increased basal plasma ACTH, suggesting that OG treatment may alter the hypothalamic pituitary adrenal axis.     

Injectable trace minerals (selenium,copper, zinc,and manganese) alleviate inflammation and oxidative stress during an aflatoxin challenge in lactating multiparous Holstein cows

Trace minerals are vital in the antioxidant response during oxidative stress; however, limited research is available on the effects of trace mineral supplementation during an aflatoxin (AF) challenge. The objective of the study was to determine the effects of 2 subcutaneous injections of 15 mg/mL of Cu, 5 mg/mL of Se, 60 mg/mL of Zn, and 10 mg/mL of Mn (Multimin 90, Multimin North America, Fort Collins, CO) given at 1 mL/90.7 kg of average body weight in response to an AF challenge. Fifty-eight Holstein cows [body weight (mean ± SD) = 734 ± 6 0kg; days in milk = 191 ± 93] were assigned to 1 of 3 treatments in a randomized complete block design. The experimental period (63 d) was divided into an adaptation phase (d 1–56) and a measurement phase (d 57–63). From d 57 to 59, cows received an AF challenge that consisted of 100 μg of aflatoxin B₁/kg of dietary dry matter intake (DMI) administered orally via balling gun. Treatments were saline injection and no AF challenge (NEG), saline injection and AF challenge (POS), and trace mineral injection and AF challenge (MM). Injections were performed subcutaneously on d 1 and 29. Milk was sampled 3 times daily from d 56 to 63, blood was sampled on d 0, 56, 60, and 63, and liver samples were taken on d 0 and 60. Two treatment orthogonal contrasts [CONT1 (NEG vs. POS) and CONT2 (POS vs. MM)] were made. Cows in NEG had lower AF excretion in milk and greater 3.5% fat-corrected milk (32.1 ± 1.37 kg/d) compared with cows in POS (28.6 ± 1.43 kg/d). Feed efficiencies (3.5% fat-corrected milk/DMI, energy-corrected milk/DMI, and milk/DMI) were greater for cows in NEG (1.42 ± 0.07, 1.46 ± 0.07, and 1.45 ± 0.07, respectively) than cows in POS (1.16 ± 0.08, 1.18 ± 0.08, and 1.22 ± 0.07, respectively). Cows in POS had greater milk urea nitrogen and blood urea nitrogen than cows in MM. Liver concentrations of Se and Fe were greater for cows in MM compared with cows in POS. Cows in MM tended to have greater plasma glutathione peroxidase activity compared with cows in POS. An upregulation of liver GPX1 was observed for cows in POS compared with cows in MM. In conclusion, subcutaneous injection of trace minerals maintained an adequate antioxidant response when an AF challenge was present.     

Neutrophil function and antibody production during the transition period: Effect of form of supplementary trace minerals and associations with postpartum clinical disease and blood metabolites

Our objectives were to evaluate the effect of the form of supplementary trace minerals—inorganic salts (STM: Co, Cu, Mn, and Zn sulfates and Na selenite) or organic (OTM: Co, Cu, Mn, Zn proteinates, and selenized yeast)—fed at 100% of recommended levels in both pre- and postpartum diets on in vitro phagocytic activity of neutrophils, and in vivo IgG responses to an ovalbumin challenge during the transition period. In addition, we investigated the associations of these immunological responses with incidence of postpartum clinical diseases and the dynamic changes of metabolic markers during the transition period. Pregnant heifers and cows (n = 273) were enrolled at 45 ± 3 d before expected calving, blocked by parity and body condition score, and allocated randomly to STM or OTM supplementation. Cows in both treatments were fed the same diet, except for the form of supplementary trace minerals. Automatic feeding gates were used to assign treatments to individual cows. Blood was collected on d ?7 ± 3 and 7 ± 3 relative to calving in a subgroup of cows (n = 131 and 133, respectively) to measure phagocytic activity of neutrophils in vitro using flow cytometry. Subcutaneous immunization with 0.5 mg of chicken egg ovalbumin was performed in a subgroup of cows (n = 181) on d ?45, ?21, and 3 relative to calving. Concentration of anti-ovalbumin IgG in serum was measured by ELISA on d ?45, ?21, 3, 7, and 21. Trace mineral concentrations in blood were measured by inductively coupled plasma mass spectrometry on d ?45, ?21, ?7, 0, 7, and 21 relative to calving. Selected metabolites were measured on d ?21, ?10, ?3, 0, 3, 7, 10, 14, and 21 relative to calving. Treatment did not affect the percentage of neutrophils performing phagocytosis on d ?7 or 7 but the median fluorescence intensity of phagocytosis on d 7 was greater for OTM than STM. We found no differences between treatments in the level of anti-ovalbumin IgG in serum on any of the sampling days. Changes in neutrophil function from prepartum to postpartum were associated with incidence of postpartum clinical disease, postpartum feed intake and milk production, concentrations of Ca, K, Se, Mn, Co, and total protein in serum. Immunoglobulin G responses to ovalbumin injections were not associated with incidence of postpartum clinical disease but were associated with body weight, feed intake, energy balance, and concentrations of nonesterified fatty acids, aspartate aminotransferase, gamma-glutamyl transpeptidase, albumin, Na, P, and Cu in serum. In conclusion, replacement of STM by OTM improved one measure of phagocytic capacity of neutrophils in vitro, which was also greater in cows that did not develop postpartum clinical disease. The associations of innate and acquired immune responses with feed intake, energy balance, and circulating concentrations of key macro and micronutrients reinforce the importance of nutritional management for the health of dairy cows during the transition period.     

The effect of trace mineral fortification level and source on performance of dairy cattle

Five hundred seventy-three cows, balanced by parity and 305-d mature equivalent at dry off, were assigned to 1 of 4 treatments: 1) 75% complexed trace minerals (CTM; 75C): Zn, Mn, Cu, and Co supplied at 75% of NRC (2001) guidelines by Zn-, Mn-, and Cu-specific AA complexes, and cobalt glucoheptonate; 2) 100% inorganic (100I): Zn, Mn, Cu, and Co supplied at 100% of NRC (2001) requirements by sulfate sources; 3) 100% complexed (100C): Zn, Mn, Cu, and Co supplied at 100% of NRC (2001) requirements by CTM; and 4) complexed/ inorganic (C/I): Zn and Cu supplied at 100% of NRC (2001) requirements using a combination of CTM and sulfates and Co and Mn supplied with sources at 9.1 and 3.3 times NRC (2001) requirements using a combination of CTM and sulfates. All percentages of Zn, Cu, Mn, and Co relative to NRC (2001) reflect supplemental contributions and do not include basal diet contributions. Experimental periods were dry period 1, full lactation 1, dry period 2, and 200 d into the subsequent lactation. Reproductive, health, and production information was collected during both lactations. Claw evaluations were conducted at trial start, 150 d into lactation 1, at the end of lactation 1, and 150 d into lactation 2. During lactation 1, C/I cows produced more milk, fat-corrected milk, energy-corrected milk, and fat than 100I cows. During lactation 2, yields of milk, fat-corrected milk, energy-corrected milk, fat, and protein were higher for 100C and C/I cows than for 75C or 100I cows. Fat percentage was highest for 100C cows with no treatment effect on protein content. During lactations 1 and 2, C/I cows had fewer days to first estrus than cows receiving the other treatments. During lactation 2, C/ I cows had fewer services per conception and days open. There were no significant effects of treatment on health. White line separation incidence was lower for 100I cows than 75C cows, whereas heel erosion was higher for the 100I cows than for the C/I cows. Fortification of trace elements with inorganic and complexed sources at or above NRC requirements improved reproductive and productive performance. In addition, cows can be supplemented with CTM at 75% of NRC requirements with no reduction in performance compared with supplementing at 100% of NRC requirements using only sulfate sources of Zn, Mn, Cu, and Co.     

Effect of source of trace minerals in either forage- or by-product–based diets fed to dairy cows: 2. Apparent absorption and retention of minerals

Eighteen multiparous cows were used in a split-plot replicated Latin square with two 28-d periods to evaluate the effects of source of supplemental Cu, Zn, and Mn (sulfates or hydroxy) on apparent absorption of minerals when fed in either a forage- or by-product–based diet. The by-product diets were formulated to have greater concentrations of NDF and lesser concentrations of starch, and specific ingredients were chosen because they were good sources of soluble fiber and β-glucans, which bind trace minerals in nonruminants. We hypothesized that hydroxy trace minerals would interact less with digesta and have greater apparent absorption compared with sulfate minerals, and the difference in apparent absorption would be greater for the by-product diet compared with the forage-based diet. During the 56-d experiment, cows remained on the same fiber treatment but source of supplemental trace mineral was different for each 28-d period; thus, all cows were exposed to both mineral treatments. During each period cows were fed no supplemental Cu, Zn, or Mn for 16 d, followed by 12 d of feeding supplemental minerals from either sulfate or hydroxy sources. Supplemental minerals for each of the mineral sources fed provided approximately 10, 35, and 32 mg/kg of supplemental Cu, Zn, and Mn, respectively, for both fiber treatments. Total Cu, Zn, and Mn dietary concentrations, respectively, were approximately 19, 65, and 70 mg/kg for the forage diets and 21, 85, and 79 for the by-product diets. Treatment had no effect on dry matter intake (24.2 kg/d) or milk production (34.9 kg/d). Cows consuming the by-product diets had greater Zn (1,863 vs. 1,453 mg/d) and Mn (1,790 vs. 1,588 mg/d) intake compared with cows fed forage diets, but apparent Zn absorption was similar between treatments. Manganese apparent absorption was greater for the by-product diets compared with the forage diets (16 vs. 11%). A fiber by mineral interaction was observed for Cu apparent absorption, as cows fed hydroxy minerals with forage diets had greater apparent absorption compared with cows fed sulfate minerals; however, the opposite was observed with the by-product diets. Source of supplemental trace minerals and type of fiber in diets affected availability of Cu and Mn and should be considered in ration formulation.     

Effects of feeding synthetic zeolite A during the prepartum period on serum mineral concentration,oxidant status,and performance of multiparous Holstein cows

The objective of this study was to determine the effects of feeding synthetic zeolite A for 3 wk before expected calving on peripartal serum mineral concentrations, hypocalcemia, oxidant status, and performance. Holstein cows (n = 55) entering their second or greater lactations were assigned randomly to 1 of 2 dietary treatments starting 21 d before expected calving: control (CON: 40% corn silage, 33% wheat straw, and 27% concentrate; n = 29) or experimental [EXP: CON plus zeolite A (X-Zelit, Protekta Inc., Lucknow, ON, Canada/Vilofoss, Graasten, Denmark; n = 26) at an inclusion rate of 3.3% of dry matter, targeting 500 g/d as-fed]. Cows were fed the same postpartum diet and housed in individual tiestalls through 28 d in milk. Cows fed EXP had higher serum Ca concentrations as parturition approached and during the immediate postpartum period. Serum P concentrations were lower for the EXP-fed cows during the prepartum period and the first 2 d of lactation, whereas serum Mg concentrations were lower than those of the CON-fed cows only during the immediate periparturient period. Cows fed EXP had decreased prevalence of subclinical hypocalcemia (SCH) from d −1 through 3 relative to day of parturition, with the largest difference occurring within the first day postpartum. Prepartum dry matter intake tended to be decreased and rumination was decreased in cows fed EXP; however; postpartum dry matter intake, rumination, milk yield, milk component yield, and colostrum measurements did not differ between treatments. Cows fed EXP tended to have increased hazard of pregnancy by 150 d in milk when controlling for parity compared with CON-fed cows; potential reproductive benefits merit further study. This study demonstrated that zeolite A supplementation during the prepartum period results in markedly improved serum Ca concentrations around parturition and similar postpartum performance compared with controls and is effective at decreasing hypocalcemia in multiparous Holstein cows.     

Effect of additional cobalt, copper, manganese, and zinc on reproduction and milk yield of lactating dairy cows receiving bovine somatotropin.

The objective of this study was to determine whether organically complexed Co, Cu, Mn, and Zn would improve the reproductive performance and milk and milk component production in lactating dairy cows that began receiving bovine somatotropin in the ninth week of lactation. Holstein (n = 50) and Jersey (n = 10) cows were blocked by breed, lactation number, and incidence of retained fetal membranes. Two diets assigned within blocks and fed from parturition until 154 d of lactation were control or control supplemented daily with 26 mg of Co as Co glucoheptonate, 125 mg of Cu as Cu-Lys, 199 mg of Mn as Mn-Met, and 359 mg of Zn as Zn-Met. Cows were fitted with electronic pressure-sensing devices in the second week of lactation for detection of estrus. Ovarian structures were determined via transrectal ultrasonography at 7-d intervals from parturition until observation of the first corpus luteum. Blood samples were taken at 7-d intervals and analyzed for plasma concentrations of progesterone, insulin, and urea nitrogen. Onset of luteal activity was identified by progesterone concentrations > or = 1 ng/ml. Retained fetal membranes increased days to first estrus (detected via electronic estrous detection), first luteal activity, and first corpus luteum in control cows but not in supplemented cows. Days to first observed estrus were greater for control cows than for supplemented cows. Days to first service, days open, days from first service to conception, services per conception, milk yield, milk components, and somatic cell counts were similar for control and supplemented cows. Supplementation with complexed trace minerals effectively reduced days to first estrus.     

Dietary replacement of soybean meal with heat-treated soybean meal or high-protein corn distillers grains on nutrient digestibility and milk composition in mid-lactation cows

Lactation diets dependent on rumen undegradable protein (RUP) sources derived from soybean meal (SBM) products are generally high in Lys and poor in Met. We conducted an experiment to evaluate the effects of increasing dietary RUP and altering digestible AA supply by inclusion of heat-treated soybean meal (HTSBM) or high-protein corn dried distillers grains with soluble (DDGS) on performance in mid-lactation dairy cows. Twenty-four Holstein cows (200 ± 40 d in milk and 30.0 ± 3.92 kg/d of milk yield) blocked according to parity, milk yield, and days in milk were used in a 3 × 3 Latin square design experiment with 21-d periods. Treatments were (1) control (CON), a diet with 6.0% RUP containing 15.9% SBM as the main protein source; (2) HTSBM, a diet with 6.7% RUP containing 4.4% HTSBM partially replacing SBM; and (3) high-protein DDGS (FP; FlexyPro, SJC Bioenergia), a diet with 6.9% RUP containing 5.34% FP partially replacing SBM and ground corn. Diets had similar crude protein (16.9%) and net energy of lactation. Data were submitted to ANOVA using the mixed procedure of SAS software (SAS Institute Inc.). Treatment differences were evaluated using orthogonal contrasts: (1) increasing RUP (SBM vs. HTSBM + FP) and (2) altering digestible AA supply (HTSBM vs. FP). Cows fed HTSBM and FP had greater intake (values in parentheses represent treatment means of CON, HTSBM, and FP, respectively) of neutral detergent fiber (7.14, 7.35, and 7.69 kg/d), crude protein (4.27, 4.37, and 4.51 kg/d), and ether extract (0.942, 0.968, and 1.04 kg/d) compared with cows fed CON. Feeding FP resulted in greater intake of neutral detergent fiber and ether extract compared with HTSBM. Cows fed HTSBM and FP had lower sorting index for feed particles <4 mm than cows fed CON (1.029, 1.008, and 1.022). Feeding FP resulted in greater intake of feed particles <4 mm compared with HTSBM. Treatments containing HTSBM or FP tended to decrease organic matter digestibility (72.4, 71.2, and 71.1%), but no other effects were detected in digestibility of neutral detergent fiber, crude protein, or ether extract. No evidence for differences among treatments was detected in excretion of purine derivatives in milk and urine. Milk yield was greater in cows fed HTSBM or FP than in cows fed CON (28.0, 28.9, and 28.8 kg/d, respectively). Cows fed HTSBM or FP tended to have greater energy-corrected milk and protein yield compared with those fed CON. Milk protein concentration was greater in DDGS cows than those in the HTSBM group (3.45 and 3.40%, respectively). No differences were detected in milk fat yield and concentration, milk urea nitrogen, feed efficiency, or serum concentrations of urea and glucose. Overall, increasing dietary RUP by feeding HTSBM or FP improved intake of nutrients and milk yield without affecting feed efficiency. Altering digestible AA supply while maintaining similar dietary RUP had negligible effects on performance of cows.     

Effects of calcareous marine algae on milk production,feed intake,energy balance,mineral status,and inflammatory markers in transition dairy cows

The objective of this experiment was to compare the effects of calcareous marine algae (CMA; Acid Buf, Celtic Sea Minerals) with a limestone-based control on feed intake, milk production, energy balance, serum mineral metabolites, and inflammatory markers in transition dairy cows. Twenty-two multiparous and 10 primiparous cows were assigned to 2 treatments from 25 d before expected parturition until 42 d postpartum. Cows were assigned to treatment according to a randomized complete block design based on parity, pre-experimental body condition score, previous 305-d milk yield, and either fat + protein yield (for multiparous cows) or predicted transmitting ability for milk yield and fat + protein yield (for primiparous cows). Cows were fed a negative dietary cation-anion difference [?50 mEq/kg] total mixed ration (TMR) based on corn silage, grass silage, and straw during the prepartum period and a 50:50 forage:concentrate TMR based on grass silage, corn silage, and concentrate during the postpartum period. The 2 dietary treatments consisted of a control (CON), which contained limestone as the primary calcium source, and CMA, in which limestone was replaced by CMA at 0.42% and 0.47% of dry matter for the pre- and postpartum periods, respectively. The dietary treatments were fed as 2 different concentrate pellets added to the TMR. Cows fed the CMA diet had higher dry matter intake in both the prepartum (+1.08 kg) and postpartum (+0.94 kg) periods compared with cows fed the CON diet. Fat yield (+0.11 kg), fat concentration (+0.43%), and 4% fat-corrected milk (+1.56 kg) were higher in cows fed CMA than in cows fed CON. The concentration of plasma serum amyloid A was reduced and that of serum P was increased on the CMA treatment compared with the CON treatment. These findings demonstrate the benefits of supplementing CMA to dairy cows during the transition period compared with a CON treatment containing limestone as the primary Ca source.